Indirect injection internal combustion engines mix fuel and air in a cavity away from the combustion chamber. This same cavity is where ignition of the fuel and air occurs. The cavity is part of a device called a prechamber. Indirect injection internal combustion engines offer advantages in simplicity of fuel injection and permit the use of designs with reduced tolerances in comparison to direct injection internal combustion engines. In addition, some spark ignition engines will use a prechamber device (either fueled or passive) to increase the ignition energy imparted to the charge in the main combustion chamber. During operation of these engines, gases will flow both into and out from the prechamber device depending on the pressure differential between the prechamber device inner cavity and the main chamber. At some point during the compression stroke, gas, including both fuel and air, will flow into the prechamber device from the main chamber. A fuel-fed prechamber device will introduce additional fuel into the prechamber device to enrich the prechamber device contents prior to ignition; a passive prechamber device will not. After ignition, the pressure inside the prechamber device will rise above the main chamber and the contents of the prechamber device, including burned and unburned fuel, will be injected into the main chamber to initiate the combustion process.
Proximity to the ignition of fuel and the combustion chamber causes significant thermal stress to the prechamber device, leading to a need to service the prechamber device at substantial cost to a user and lengthy down time for a user. Thus, there is a need for an improved prechamber capable of reducing thermal stresses to improve the life of a prechamber device.